A couple of painful deadlock issues are now prevented as noted in KBs 978517 and 979219.
Two Store crash scenarios were repaired; see KBs 978528 & 979520.
Several improvements for meeting request issues are also included in this rollup.
For those of you running Forefront, be sure you perform these important steps from the command line in the Forefront directory before and after this rollup's installation process. Without these steps, Exchange services for Information Store and Transport will not start back up. You will need to disable ForeFront via "fscutility /disable" before installing the patch and then re-enable after the patch by running "fscutility /enable" to start it up again post installation.
Again, you can read the list of issues fixed up in KB979784.